Cleaning the fuel tank

Breezy · October 04, 2016, 06:37:41 PM

Just finished cleaning the fuel tank on my 1982 VF45. Oh yes it was bad, but the Apple Cider Vinegar did a wonderful job of removing the surface rust inside the tank (3 days sitting). I did my best to remove all the remints of the cider with hot water and then with distilled water and now want to know if anyone has a good gas tank sealing product that you may of used to help keep the rust at bay.
also my fuel filter was caked full of rust and now I question on having to remove the backup 1 gallon tank (reserve). Would it possible to just remove the low fuel sender and fill it with vinegar and flush while on the bike? I thinking if the tank was crappy so is the backup tank.
Thanks much

Drive safe

MagnaMan · October 04, 2016, 10:47:36 PM

I wouldn't seal it. I think the cream sealers just cause more problems than they are worth. For one they often block the gas tank vent tube (Search for a thread here about that). I've also seen some break down with the ethanol and then you have plastic bits in your gas and your carbs.

I cleaned my tank several years ago of surface rust and just left it alone, keeping it filled with gas and not letting it set long enough for moisture to collect inside. I haven't noticed any of the rust returning, at least not where I can see.

If you're worried you could by some flexible fuel line and install a fuel filter between the pet cock and the carbs.

TLRam1 · October 05, 2016, 02:15:36 AM

If you seal it use Por 15.

Breezy · October 05, 2016, 10:52:12 AM

I agree that sealing a tank has its problems and your mention of the vent is valid but I also believe if using the right product one can achieve good results. I have a plan for the vent to stay open, if I can devise a long type rod that can be inserted from the back side all the way up to the end of the vent to keep it open without getting it glued in or just keep blowing air into the valve to keep it from blocking.
I have read up on the POR 15 and seems to be a good choice and sounds as it is compatible with Ethanol, of course as MagnaMan said we don't want any plastic crap floating around later on. Hard decision.

Thanks

lragan · October 05, 2016, 12:36:33 PM

I despise ethanol. I could go on for hours why there should be no mandate.

The one good thing about it, though, is it absorbs water and lets it pass through the carb and engine without damage. Back where I was raised, we would put a bit of ethanol in our gas tractors' tanks in the fall, even though we topped them off, just for this purpose.

If you keep the tank full when you park the bike, you should not experience corrosion due to water.

MagnaMan · October 05, 2016, 01:28:13 PM

I bought some POR to seal the tank in my 63 Chevy truck. I bought it from a radiator shop in Waller, TX that has garnered a reputation in the restoration of antique auto fuel tanks. The guy at the shop told me that the sealant was doomed to fail if you did not use the POR prep fluid, which I think costs even more than the sealer. He could have been just trying to sell me the prep fluid too. But was he was pretty helpful in telling me detailed instructions for how to do it right. And he mentioned he had seen several jobs where the sealer bubbled or peeled because they didn't prep it right.

I haven't actually used the POR because I scored another tank from the same year that is immaculate. The POR has a limited shelf life so I'd be willing to hook you up for a deal, because I'd rather let it go then let it go bad.

That said I still don't know that I'd do it. The truck fuel tank is much less complex than a Magna tank. There are only about 6 flat surfaces for the sealer to flow over. With the Magna tank you have more surface changes to coat so it may be more of a challenge to get it to cover before it sets and without leaving a lot of surplus in the bottom edges of the tank.

Either way, good luck!

MagnaMan · October 05, 2016, 01:52:09 PM

Sorry. I jut realized that I'm talking about 3rd gen Magna tank. The first gen Magna tank may be a lot less complex inside.

Breezy · October 05, 2016, 09:40:22 PM

Well I am going to hold off now on the sealing of the tank as when today I was stripping the paint and when I got to the steel I found more body filler that a cream filled Twinkie. Yeah the filler was showing rust color penetrating out of the filler and I think the paint with a clear coat was the only thing keeping it from leaking. I took a dental pick used for o ring removal and pulled a loose corner up and it is junk. I think the holes were pinholes at one time but now they are holes. So cleaning the tank was a waste as this tank is trash. Anyone have a tank for sale. Thanks guys.